Tip # 11 No check engine light but vehicle keeps stalling at stops

If you are experiencing stalling at stops but don’t see any check engine light in your dash panel, check your fuel regulator connected in the fuel rail on top of your engine. This regulator controls the fuel pressure of your fuel by disconnecting the vacuum hose hooked to it. When disconnected, it should raise the fuel pressure and lower it as soon as you install the vacuum hose back.

To test your fuel regulator, start your engine and warm it up to say 15-20 minutes. Then when idling, remove the vacuum hose connected to it. If you see a spit of fuel coming out of the fuel regulator or end of the hose, it shows the fuel regulator rubber diaphragm is damaged and should be replaced. When damaged, the end of the vacuum hose will also smell gas.

Other symptoms of a bad fuel regulator are:

Long hard starts especially if the engine is flooded if the diaphragm is ruptured.
Black smoke at your tail pipe after you got it started.


Shown here is an example of a fuel regulator.

Note the fuel rail also connects to your fuel injectors. When testing fuel pressure, use a fuel gage hook up to the schrader valve of the fuel rail. (This valve is similar to the air valve for inflating air in your tires).